Brown says he didn't even see the truck coming. "I became aware of the danger when Tessy" — yes, that's what he calls his Tesla — "alerted me with the 'immediately take over' warning chime and the car swerving to the right to avoid the side collision," Brown wrote in the video description.

Tesla has digitized many components of the car, including the brakes, steering and motor function, in order to prevent collisions with the front and side of the car, according to its site. Eventually, the company wants to push beyond autopilot, into fully autonomous vehicles.

Since launching autopilot in the fall of 2015, Brown, a Model S owner, has posted several videos to YouTube documenting his car's capabilities. While "Tessy" helped Brown avoid an accident with the truck, Brown acknowledges its limitations: In another video he shows the car's autopilot feature having difficulty making sharp turns in the dark.